Before this fix, the test output for perfschema.server_init would
vary between executions, because some of the objects tested were
not guaranteed to exist in all configurations / code paths.
This fix removes these weak tests.
Also, comments referring to abandonned code have been cleaned up.
Before this fix, the test output for perfschema.server_init would
vary between executions, because some of the objects tested were
not guaranteed to exist in all configurations / code paths.
This fix removes these weak tests.
Also, comments referring to abandonned code have been cleaned up.
Before this fix, the server could crash inside a memcpy when reading data
from the EVENTS_WAITS_CURRENT / HISTORY / HISTORY_LONG tables.
The root cause is that the length used in a memcpy could be corrupted,
when another thread writes data in the wait record being read.
Reading unsafe data is ok, per design choice, and the code does sanitize
the data in general, but did not sanitize the length given to memcpy.
The fix is to also sanitize the schema name / object name / file name
length when extracting the data to produce a row.
Before this fix, the server could crash inside a memcpy when reading data
from the EVENTS_WAITS_CURRENT / HISTORY / HISTORY_LONG tables.
The root cause is that the length used in a memcpy could be corrupted,
when another thread writes data in the wait record being read.
Reading unsafe data is ok, per design choice, and the code does sanitize
the data in general, but did not sanitize the length given to memcpy.
The fix is to also sanitize the schema name / object name / file name
length when extracting the data to produce a row.
Implemented post review comments.
Added --force to the mysql_upgrade command in the test scripts,
so that the test output does not depends on whether other tests involving an
upgrade have been executed or not in the same test suite execution.
Implemented post review comments.
Added --force to the mysql_upgrade command in the test scripts,
so that the test output does not depends on whether other tests involving an
upgrade have been executed or not in the same test suite execution.
With recent changes in the performance schema default sizing parameters,
the memory used by a mysqld binary increased accordingly.
This negatively affects the MTR test suite,
because running several tests in parallel now consumes more ressources.
The fix is to leave the default production values unchanged,
and to configure the MTR environment to limit memory
used when running tests in the test suite, which is ok
because only a few objects are typically used within a test script.
This fix:
- changed the default configuration in MTR to use less memory
- adjusted the performance schema tests accordingly
Note that 1,000 mutex instances was too short and caused test failures
in the past in team trees, so the default used is now 10,000 in MTR.
The amount of memory used by the performance schema itself
can be observed with the statement SHOW ENGINE PERFORMANCE_SCHEMA STATUS
With recent changes in the performance schema default sizing parameters,
the memory used by a mysqld binary increased accordingly.
This negatively affects the MTR test suite,
because running several tests in parallel now consumes more ressources.
The fix is to leave the default production values unchanged,
and to configure the MTR environment to limit memory
used when running tests in the test suite, which is ok
because only a few objects are typically used within a test script.
This fix:
- changed the default configuration in MTR to use less memory
- adjusted the performance schema tests accordingly
Note that 1,000 mutex instances was too short and caused test failures
in the past in team trees, so the default used is now 10,000 in MTR.
The amount of memory used by the performance schema itself
can be observed with the statement SHOW ENGINE PERFORMANCE_SCHEMA STATUS
Before this fix, the server did not recognize 'short' (as in -a)
options but only 'long' (as in --ansi) options
in the startup command line, due to earlier changes in 5.5
introduced for the performance schema.
The root cause is that handle_options() did not honor the
my_getopt_skip_unknown flag when parsing 'short' options.
The fix changes handle_options(), so that my_getopt_skip_unknown is
honored in all cases.
Note that there are limitations to this,
see the added doxygen documentation in handle_options().
The current usage of handle_options() by the server to
parse early performance schema options fits within the limitations.
This has been enforced by an assert for PARSE_EARLY options, for safety.
Before this fix, the server did not recognize 'short' (as in -a)
options but only 'long' (as in --ansi) options
in the startup command line, due to earlier changes in 5.5
introduced for the performance schema.
The root cause is that handle_options() did not honor the
my_getopt_skip_unknown flag when parsing 'short' options.
The fix changes handle_options(), so that my_getopt_skip_unknown is
honored in all cases.
Note that there are limitations to this,
see the added doxygen documentation in handle_options().
The current usage of handle_options() by the server to
parse early performance schema options fits within the limitations.
This has been enforced by an assert for PARSE_EARLY options, for safety.
Before this fix, some tests failed due to lack of instrumentation slots
in the performance schema, because the default sizing was too low.
Now that more code has been instrumented, the default sizing has to be adjusted
to match the current instrumentation consumption.
This change:
- increases the number of rwlock classes from 20 to 30,
- increases the number of rwlock and mutex instances to 1 million.
Both are to account for the volume of data instrumented
when the innodb storage engine is used (because of the innodb buffer pool).
Adjusted the test output accordingly.
Before this fix, some tests failed due to lack of instrumentation slots
in the performance schema, because the default sizing was too low.
Now that more code has been instrumented, the default sizing has to be adjusted
to match the current instrumentation consumption.
This change:
- increases the number of rwlock classes from 20 to 30,
- increases the number of rwlock and mutex instances to 1 million.
Both are to account for the volume of data instrumented
when the innodb storage engine is used (because of the innodb buffer pool).
Adjusted the test output accordingly.
temp table
This patch introduces two key changes in the replication's behavior.
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
temp table
This patch introduces two key changes in the replication's behavior.
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
TABLES <list> WITH READ LOCK are incompatible".
The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.
This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.
This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.
As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.
Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.
mysql-test/include/handler.inc:
Adjusted test case after changing status which is set
when FLUSH TABLES waits for tables to be flushed from
"Flushing tables" to "Waiting for table".
mysql-test/r/flush.result:
Added test which checks that "flush tables <list> with
read lock" is compatible with active "flush tables with
read lock" but not vice-versa. This test also covers
bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
<list> WITH READ LOCK are incompatible".
mysql-test/r/mdl_sync.result:
Added scenarios in which wait for table to be flushed
causes deadlocks to the coverage of MDL deadlock detector.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
Adjusted test results after removal of COND_refresh
condition variable.
mysql-test/suite/perfschema/r/server_init.result:
Adjusted test and its results after removal of COND_refresh
condition variable.
mysql-test/suite/perfschema/t/server_init.test:
Adjusted test and its results after removal of COND_refresh
condition variable.
mysql-test/t/flush.test:
Added test which checks that "flush tables <list> with
read lock" is compatible with active "flush tables with
read lock" but not vice-versa. This test also covers
bug #52044 "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
<list> WITH READ LOCK are incompatible".
mysql-test/t/kill.test:
Adjusted test case after changing status which is set
when FLUSH TABLES waits for tables to be flushed from
"Flushing tables" to "Waiting for table".
mysql-test/t/lock_multi.test:
Adjusted test case after changing status which is set
when FLUSH TABLES waits for tables to be flushed from
"Flushing tables" to "Waiting for table".
mysql-test/t/mdl_sync.test:
Added scenarios in which wait for table to be flushed
causes deadlocks to the coverage of MDL deadlock detector.
sql/ha_ndbcluster.cc:
Adjusted code after adding one more parameter for
close_cached_tables() call - timeout for waiting for
table to be flushed.
sql/ha_ndbcluster_binlog.cc:
Adjusted code after adding one more parameter for
close_cached_tables() call - timeout for waiting for
table to be flushed.
sql/lock.cc:
Removed COND_refresh condition variable. See comment
for sql_base.cc for details.
sql/mdl.cc:
Now MDL deadlock detector takes into account information
about waits for table flushes when searching for deadlock.
To implement this change:
- Declaration of enum_deadlock_weight and
Deadlock_detection_visitor were moved to mdl.h header
to make them available to the code in table.cc which
implements deadlock detector traversal through edges
of waiters graph representing waiting for flush.
- Since now MDL_context may wait not only for metadata
lock but also for table to be flushed an abstract
Wait_for_edge class was introduced. Its descendants
MDL_ticket and Flush_ticket incapsulate specifics
of inspecting waiters graph when following through
edge representing wait of particular type.
We no longer require global IX metadata lock when acquiring
SNW or SNRW locks. Such locks are needed only when metadata
locks of these types are upgraded to X locks. This allows
to use SNW locks in FLUSH TABLES <list> WITH READ LOCK
implementation and keep the latter compatible with global
read lock.
sql/mdl.h:
Now MDL deadlock detector takes into account information
about waits for table flushes when searching for deadlock.
To implement this change:
- Declaration of enum_deadlock_weight and
Deadlock_detection_visitor were moved to mdl.h header
to make them available to the code in table.cc which
implements deadlock detector traversal through edges
of waiters graph representing waiting for flush.
- Since now MDL_context may wait not only for metadata
lock but also for table to be flushed an abstract
Wait_for_edge class was introduced. Its descendants
MDL_ticket and Flush_ticket incapsulate specifics
of inspecting waiters graph when following through
edge representing wait of particular type.
- Deadlock_detection_visitor now has m_table_shares_visited
member which allows to support recursive locking for
LOCK_open. This is required when deadlock detector
inspects waiters graph which contains several edges
representing waits for flushes or needs to come through
the such edge more than once.
sql/mysqld.cc:
Removed COND_refresh condition variable. See comment
for sql_base.cc for details.
sql/mysqld.h:
Removed COND_refresh condition variable. See comment
for sql_base.cc for details.
sql/sql_base.cc:
Changed approach to how threads are waiting for table
to be flushed. Now thread that wants to wait for old
table to go away subscribes for notification by adding
Flush_ticket to table's share and waits using
MDL_context::m_wait object. Once table gets flushed
(i.e. all tables are closed and table share is ready
to be destroyed) all such waiters are notified
individually.
Thanks to this change MDL deadlock detector can take
such waits into account.
To implement this/as result of this change:
- tdc_wait_for_old_versions() was replaced with
tdc_wait_for_old_version() which waits for individual
old share to go away and which is called by open_table()
after finding out that share is outdated. We don't
need to perform back-off before such waiting thanks
to the fact that deadlock detector now sees such waits.
- As result Open_table_ctx::m_mdl_requests became
unnecessary and was removed. We no longer allocate
copies of MDL_request objects on MEM_ROOT when
MYSQL_OPEN_FORCE_SHARED/SHARED_HIGH_PRIO flags are
in effect.
- close_cached_tables() and tdc_wait_for_old_version()
share code which implements waiting for share to be
flushed - the both use TABLE_SHARE::wait_until_flush()
method. Thanks to this close_cached_tables() supports
timeouts and has extra parameter for this.
- Open_table_context::OT_MDL_CONFLICT enum element was
renamed to OT_CONFLICT as it is now also used in cases
when back-off is required to resolve deadlock caused
by waiting for flush and not metadata lock.
- In cases when we discover that current connection tries
to open tables from different generation we now simply
back-off and restart process of opening tables. To
support this Open_table_context::OT_REOPEN_TABLES enum
element was added.
- COND_refresh condition variable became unnecessary and
was removed.
- mysql_notify_thread_having_shared_lock() no longer wakes
up connections waiting for flush as all such connections
can be waken up by deadlock detector if necessary.
sql/sql_base.h:
- close_cached_tables() now has one more parameter -
timeout for waiting for table to be flushed.
- Open_table_context::OT_MDL_CONFLICT enum element was
renamed to OT_CONFLICT as it is now also used in cases
when back-off is required to resolve deadlock caused
by waiting for flush and not metadata lock.
Added new OT_REOPEN_TABLES enum element to be used in
cases when we need to restart open tables process even
in the middle of transaction.
- Open_table_ctx::m_mdl_requests became unnecessary and
was removed.
sql/sql_class.h:
Added assert ensuring that we won't use LOCK_open mutex
with THD::enter_cond(). Otherwise deadlocks can arise in
MDL deadlock detector.
sql/sql_parse.cc:
Changed FLUSH TABLES <list> WITH READ LOCK to take SNW
metadata locks instead of X locks on tables to be flushed.
Since we no longer require global IX lock to be taken
when SNW locks are taken this makes this statement
compatible with FLUSH TABLES WITH READ LOCK statement.
Since SNW locks allow other connections to have table
opened FLUSH TABLES <list> WITH READ LOCK now has to
wait during open_tables() for old version to go away.
Such waits can lead to deadlocks which will be detected
by MDL deadlock detector which now takes waits for table
to be flushed into account.
Also adjusted code after adding one more parameter for
close_cached_tables() call - timeout for waiting for
table to be flushed.
sql/sql_yacc.yy:
FLUSH TABLES <list> WITH READ LOCK now needs only SNW
metadata locks on tables.
sql/sys_vars.cc:
Adjusted code after adding one more parameter for
close_cached_tables() call - timeout for waiting for
table to be flushed.
sql/table.cc:
Implemented new approach to how threads are waiting for
table to be flushed. Now thread that wants to wait for
old table to go away subscribes for notification by
adding Flush_ticket to table's share and waits using
MDL_context::m_wait object. Once table gets flushed
(i.e. all tables are closed and table share is ready
to be destroyed) all such waiters are notified
individually. This change allows to make such waits
visible inside of MDL deadlock detector.
To do it:
- Added list of waiters/Flush_tickets to TABLE_SHARE
class.
- Changed free_table_share() to postpone freeing of
share memory until last waiter goes away and to
wake up subscribed waiters.
- Added TABLE_SHARE::wait_until_flushed() method which
implements subscription to the list of waiters for
table to be flushed and waiting for this event.
Implemented interface which allows to expose waits for
flushes to MDL deadlock detector:
- Introduced Flush_ticket class a descendant of
Wait_for_edge class.
- Added TABLE_SHARE::find_deadlock() method which allows
deadlock detector to find out what contexts are still
using old version of table in question (i.e. to find
out what contexts are waited for by owner of
Flush_ticket).
sql/table.h:
In order to support new strategy of waiting for table flush
(see comment for table.cc for details) added list of
waiters/Flush_tickets to TABLE_SHARE class.
Implemented interface which allows to expose waits for
flushes to MDL deadlock detector:
- Introduced Flush_ticket class a descendant of
Wait_for_edge class.
- Added TABLE_SHARE::find_deadlock() method which allows
deadlock detector to find out what contexts are still
using old version of table in question (i.e. to find
out what contexts are waited for by owner of
Flush_ticket).
TABLES <list> WITH READ LOCK are incompatible".
The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.
This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.
This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.
As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.
Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.
The reason for the bug above is unclear but
- Modify pfs_upgrade so that it's result is easier to analyze in case something fails
- Fix several minor weaknesses which could cause that a successing test (either an
already existing or a to be developed one) fails because of imperfect cleanup,
too slow disconnected sessions etc.
should either fix the bug or reduce it's probability or at least
make the analysis of failures easier.
mysql-test/suite/perfschema/include/upgrade_check.inc:
New include file which contains redundant stuff taken from pfs_upgrade.test.
Remove any file which might harm analysis of suspicious results.
mysql-test/suite/perfschema/r/query_cache.result:
Updated results
mysql-test/suite/perfschema/r/selects.result:
Updated results
mysql-test/suite/perfschema/t/bad_option_1.test:
Add the missing remove_file at beginning and end of test.
mysql-test/suite/perfschema/t/bad_option_2.test:
Add the missing remove_file at beginning and end of test.
mysql-test/suite/perfschema/t/global_read_lock.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/pfs_upgrade.test:
- Move redundant actions to include/upgrade_check.inc
- Add preemptive removal of files
mysql-test/suite/perfschema/t/privilege.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/query_cache.test:
Add "flush status" so that counters are reset. (./mtr --repeat=2 perfschema.query_cache failed)
mysql-test/suite/perfschema/t/read_only.test:
Add a wait routine which ensures that the disconnect is really completed when the test ends.
mysql-test/suite/perfschema/t/selects-master.opt:
Needed for running with enabled event-scheduler
mysql-test/suite/perfschema/t/selects.test:
- Correct the sub test for the EVENT scheduler
- Replace "sleep" by wait_routine
- Add premptive cleanups like "DROP ... IF EXISTS ..."
The reason for the bug above is unclear but
- Modify pfs_upgrade so that it's result is easier to analyze in case something fails
- Fix several minor weaknesses which could cause that a successing test (either an
already existing or a to be developed one) fails because of imperfect cleanup,
too slow disconnected sessions etc.
should either fix the bug or reduce it's probability or at least
make the analysis of failures easier.
